Top 87 Spring Interview Questions And Answers

Question 1

What is Spring?

Accepted Answer

**Spring** is an open source development framework for enterprise Java. The core features of the Spring Framework can be used in developing any Java application, but there are extensions for building web applications on top of the Java EE platform. Spring framework targets to make J2EE development easier to use and promote good programming practice by enabling a POJO-based (Plain Old Java Object) programming model.

Question 2

What are benefits of using Spring?

Accepted Answer

Following is the list of few of the great benefits of using Spring Framework:
*   **Lightweight** − Spring is lightweight when it comes to size and transparency. The basic version of spring framework is around 2MB.
*   **Inversion of control (IOC)** − Loose coupling is achieved in spring using the technique Inversion of Control. The objects give their dependencies instead of creating or looking for dependent objects.
*   **Aspect oriented (AOP)** − Spring supports Aspect oriented programming and enables cohesive development by separating application business logic from system services.
*   **Container** − Spring contains and manages the life cycle and configuration of application objects.
*   **MVC Framework** − Spring's web framework is a well-designed web MVC framework, which provides a great alternative to web frameworks such as Struts or other over-engineered or less popular web frameworks.
*   **Transaction Management** − Spring provides a consistent transaction management interface that can scale down to a local transaction (using a single database, for example) and scale up to global transactions (using JTA, for example).
*   **Exception Handling** − Spring provides a convenient API to translate technology-specific exceptions (thrown by JDBC, Hibernate, or JDO, for example) into consistent, unchecked exceptions.

Question 3

What is Spring Boot?

Accepted Answer

**Spring Boot** is a project that provides a pre-configured set of frameworks to reduce boilerplate configuration so that you can have a Spring application up and running with the smallest amount of code.

Question 4

What is default scope of bean in Spring framework?

Accepted Answer

The default scope of bean is **Singleton** for Spring framework.

Question 5

What is the DispatcherServlet and what is it used for?

Accepted Answer

The `DispatcherServlet` is an implementation of the Front Controller design pattern that handles all incoming web request to a Spring MVC application. A Front Controller pattern (see Enterprise application design pattern) is a common pattern in web applications whose job is to receive all request and route it to different components of the application for actual processing.

In Spring MVC, `DispatcherServlet` is used for finding the correct Controller to process a request, which it does with the help of handler mapping, e.g. the `@RequestMapping` annotation.

Question 6

Do you need spring-mvc.jar in your classpath or is it part of spring-core?

Accepted Answer

The `spring-mvc.jar` is not part of spring-core, which means that if you want to use Spring MVC framework in your Java project, you must include `spring-mvc.jar` in your application's classpath. In a Java web application, `spring-mvc.jar` is usually placed inside the `/WEB-INF/lib` folder.

Question 7

What is Spring Security?

Accepted Answer

**Spring Security** is a separate module of the Spring framework that focuses on providing authentication and authorization methods in Java applications. It also takes care of most of the common security vulnerabilities such as CSRF attacks.

To use Spring Security in web applications, you can get started with a simple annotation: _@EnableWebSecurity_.

Question 8

What is the purpose of the Core Container module?

Accepted Answer

The core container provides the essential functionality of the Spring framework. A primary component of the core container is the `BeanFactory`, an implementation of the Factory pattern. The `BeanFactory` applies the _Inversion of Control_ (IOC) pattern to separate an application's configuration and dependency specification from the actual application code.

Question 9

What in the world are Spring beans?

Accepted Answer

Spring beans are just object instances that are managed by the Spring container, namely, they are created and wired by the framework and put into a "bag of objects" (the container) from where you can get them later.

The "wiring" part there is what dependency injection is all about, what it means is that you can just say "I will need this thing" and the framework will follow some rules to get you the proper instance.

Question 10

What does a bean definition contain?

Accepted Answer

The bean definition contains the information called configuration metadata which is needed for the container to know the followings −

*   How to create a bean
*   Bean's lifecycle details
*   Bean's dependencies

Top 87 Spring Interview Questions

What is Spring?

What are benefits of using Spring?

How is event handling done in Spring?

What are ORM's Spring supports?

What are the different modules in Spring framework?

What is Spring MVC framework?

Explain the @Controller annotation.

How do you provide configuration metadata to the Spring Container?

How to integrate Java Server Faces (JSF) with Spring?

What is Application Context?

What is the purpose of the Core Container module?

What in the world are Spring beans?

Do you need spring-mvc.jar in your classpath or is it part of spring-core?

What is the DispatcherServlet and what is it used for?

What is Spring Boot?

What is Spring Security?

What does a bean definition contain?

What do you mean by Bean wiring ?

What is a View and what's the idea behind supporting different types of View?

What is default scope of bean in Spring framework?

What are Spring beans?

Explain @RequestMapping annotation.

How does the scope Prototype work?**

What is the Model?

What is Spring JDBCTemplate class and how to use it?

How to validate form data in Spring Web MVC Framework?

What is AOP?

What is Spring IoC container?

How is the right View chosen when it comes to the rendering phase?

What is the typical Bean life cycle in Spring Bean Factory Container?

What is Aspect?

Why are controllers testable artifacts?

How to handle exceptions in Spring MVC Framework?

What are the types of the transaction management Spring supports?

What is the difference between Bean Factory and ApplicationContext?

Name some of the Design Patterns used in the Spring Framework?

How would you relate Spring MVC Framework to MVC architecture?

What is bean auto wiring?

How do you define a bean scope?

How can you inject Java Collection in Spring?

Does Spring Bean provide thread safety?

What is Spring IoC Container?

Can we send an Object as the response of Controller handler method?

Explain Bean lifecycle in Spring framework

Is the DispatcherServlet instantiated via an application context?

What is the difference between Bean Factory and Application Context?

What do you mean by Auto Wiring?

Explain the difference between spring @Controller and @RestController annotation

What is the purpose of the session scope?

What is the use of WebClient and WebTestClient?

What is Controller in Spring MVC framework?

What is Bean Factory?

Describe some of the standard Spring events

What are the differences between @RequestParam and @PathVariable?

What are the different types of Advices?

Compare @Component (v2.5) versus @Bean (v 3.0)

What is Spring WebFlux?

What are the disadvantages of using Reactive Streams?

What is the difference between concern and cross-cutting concern in Spring AOP?

What is Weaving?

Is Spring 5 compatible with older versions of Java?

How does Spring 5 integrate with JDK 9 modularity?

What are Aspect, Advice, Pointcut, and JoinPoint in AOP?

What are some benefits of using Spring Transactions?

What are inner beans in Spring?

What is Join point?

What is Aspect-Oriented Programming?

What’s the difference between @Component, @Controller, @Repository & @Service annotations in Spring?

How is an incoming request mapped to a controller and mapped to a method?

What is Spring MVC Interceptor and how to use it?

What are some of the important Spring annotations you have used?

What is the default scope in the web context?

What are the limitations with autowiring?

What are different Modes of auto wiring?

What bean scopes does Spring support? Explain them.

What is reactive programming?

What are the advantages of Spring MVC over Struts MVC ?

Can we use both Web MVC and WebFlux in the same application?

Where does the @Transactional annotation belong?